Rodger J. McNab

Towards the digital music library: tune retrieval from acoustic input

Music is traditionally retrieved by title, composer or subjectclassification. It is possible, with current technology, toretrieve music from a database on the basis of a few notes sung orhummed into a microphone. This paper describes the implementationof such a system, and discusses several issues pertaining to musicretrieval. We first describe an interface that transcribes acousticinput into standard music notation. We then analyze string matchingrequirements for ranked retrieval of music and present the resultsof an experiment which tests how accurately people sing well knownmelodies. The performance of several string matching criteria areanalyzed using two folk song databases. Finally, we describe aprototype system which has been developed for retrieval of tunesfrom acoustic input.

A transaction log analysis of a digital library

Abstract.As experimental digital library testbeds gain wider acceptance and develop significant user bases, it becomes important to investigate the ways in which users interact with the systems in practice. Transaction logs are one source of usage information, and the information on user behavior can be culled from them both automatically (through calculation of summary statistics) and manually (by examining query strings for semantic clues on search motivations and searching strategy). We have conducted a transaction log analysis on user activity in the Computer Science Technical Reports Collection of the New Zealand Digital Library, and report insights gained and identify resulting search interface design issues. Specifically, we present the user demographics available with our library, discuss the use of operators and search options in queries, and examine patterns in query construction and refinement. We also describe common mistakes in searching, and examine the distribution of query terms appearing in the logs.

A compression-based algorithm for Chinese word segmentation

Chinese is written without using spaces or other word delimiters. Although a text may be thought of as a corresponding sequence of words, there is considerable ambiguity in the placement of boundaries. Interpreting a text as a sequence of words is beneficial for some information retrieval and storage tasks: for example, full-text search, word-based compression, and keyphrase extraction. We describe a scheme that infers appropriate positions for word boundaries using an adaptive language model that is standard in text compression. It is trained on a corpus of presegmented text, and when applied to new text, interpolates word boundaries so as to maximize the compression obtained. This simple and general method performs well with respect to specialized schemes for Chinese language segmentation.

Towards a digital library of popular music

Digital libraries of music have the potential to capture popular imagination in ways that more scholarly libraries cannot. We are working towards a comprehensive digital library of musical material, including popular music. We have developed new ways of collecting musical material, accessing it through searching and browsing, and presenting the results to the user. We work with different representations of music: facsimile images of scores, the internal representation of a music editing program, page images typeset by a music editor, MIDI files, audio files representing sung user input, and textual metadata such as title, composer and arranger, and lyrics. This paper describes a comprehensive suite of tools that we have built for this project. These tools gather musical material, convert between many of these representations, allow searching based on combined musical and textual criteria, and help present the results of searching and browsing. Although we do not yet have a single fully-blown digital music library, we have built several exploratory prototype collections of music, some of them very large (100,000 tunes), and critical components of the system have been evaluated.

Usage analysis of a digital library

ABSTRACT We analyse transaction logs for a large full-text documentcollection for Computer Science researchers. We reportinsights gained from this analysis and identify resulting searchinterface design issues. KEYWORDS: transaction log analysis, search interface,usage analysis. INTRODUCTION There is extensive literature on transaction log analysis ofOPACs (see [3] for an overview). However, little work of thisnature has been applied to digital libraries—likely becausemany digital libraries have only recently attained a usage levelsuitable for log analysis. Since log analysis provides insightinto user search behaviour it is useful in the design andconsideration of query interfaces.We apply transaction log analysis techniques to the NewZealand Digital Library (http://www.nzdl.org). We focus onthe Computer Science Technical Reports (CSTR) collectionwhich contains almost 46000 publically available ComputerScience technical reports from around the world. Because thecollection is not formally catalogued users carry out keywordsearches within the

An Analysis of Usage of a Digital Library

As experimental digital library testbeds gain wider acceptance and develop significant user bases, it becomes important to investigate the ways in which users interact with the systems in practice. Transaction logs are one source of usage information, and the information on user behaviour can be culled from them both automatically (through calculation of summary statistics) and manually (by examining query strings for semantic clues on search motivations and searching strategy). We conduct a transaction log analysis on user activity in the Computer Science Technical Reports Collection of the New Zealand Digital Library, and report insights gained and identify resulting search interface design issues.

Tune Retrieval in the Multimedia Library

Musical scores are traditionally retrieved by title, composer or subject classification. Just as multimedia computer systems increase the range of opportunities available for presenting musical information, so they also offer new ways of posing musically-oriented queries. This paper shows how scores can be retrieved from a database on the basis of a few notes sung or hummed into a microphone. The design of such a facility raises several interesting issues pertaining to music retrieval. We first describe an interface that transcribes acoustic input into standard music notation. We then analyze string matching requirements for ranked retrieval of music and present the results of an experiment which tests how accurately people sing well known melodies. The performance of several string matching criteria are analyzed using two folk song databases. Finally, we describe a prototype system which has been developed for retrieval of tunes from acoustic input and evaluate its performance.

A distributed digital library architecture incorporating different index styles

The New Zealand Digital Library offers several collections of information over the World Wide Web. Although full-text indexing is the primary access mechanism, musical collections can also be accessed through a novel melody retrieval system. In offering this service over a three-year period, we have had to face many practical challenges in building, maintaining and administering diverse collections of different kinds of information, involving different search and retrieval systems, with different user interfaces. This paper describes the design of the software we have built to support the service. Interface server programs provide a uniform interface between the search engine and the client, irrespective of the nature of the collection. Search engines that embody completely different index styles operate under a single distributed framework-we describe as examples MG (Managing Gigabytes), a full-text retrieval system, and the MR (Melody Retrieval) system. A flexible protocol for communicating between an interface server and a search engine is defined. The resulting architecture simplifies library administration and the creation of new collections by providing a unified framework under which vastly different user interfaces and search engines can co-exist in a distributed computing environment.

A public library based on full-text retrieval

•We avoid manual processing of source material, and avoid making assumptions about the document repositories from which it is collected; for example, we do not require bibliographic metadata. •Access is via a full-text index of the entire contents of each document, rather than document surrogates. •We are concerned with user interface aspects and the real needs of library users. •Our systems must operate in geographically remote locations with high Internet costs—an environment in which the benefits of networked library technology is especially striking. •We aim to produce a library scheme that operates on small, inexpensive servers.

Visualising sequences of queries: a new tool for information retrieval

This paper describes a system that uses visualisation to assist a user in dealing with the information returned from a search engine. The users queries, and the documents they return, are represented by a 3D spatial structure that shows their relationships and provides a way of accessing and exploring the documents retrieved. It is implemented to work with the New Zealand Digital Library, a set of large document collections that is available over the Web. The visualisation scheme is a Java applet that is updated dynamically whenever the user makes a new search, and can be browsed alongside the search engine.